凝聚环连接着姐妹DNA分子
Christian H Haering1, Ana-Maria Farcas, Prakash Arumugam
1University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK.
Nature
|July 4, 2008
概括
凝聚素是一种对细胞分裂至关重要的蛋白质复合体,形成了一个圈圈,捕获姐妹DNA分子. 这项研究以化学方式关闭了凝聚素环,证实了它在分化过程中保持DNA链在一起的作用.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 遗传学 遗传学 是一个
背景情况:
- 姐妹染色体凝聚力对于精确的染色体分离在分裂过程中至关重要.
- 凝聚素复合体由Scc1,Smc1和Smc3子单元组成,形成一个三部分环结构.
- 环捕获模型提出,凝聚性环绕着姐妹DNA分子来保持凝聚力.
研究的目的:
- 为了实验验证凝聚力函数的环捕获模型.
- 研究凝聚素调解姐妹染色体凝聚力的结构机制.
主要方法:
- 使用特定站点的交叉连接,创建共封闭的凝聚环.
- 在Scc1,Smc1和Smc3子单元之间的接口上引入了化学连接.
- 评估了改性凝聚环的稳定性和DNA结合性质.
主要成果:
- 成功生成了共价闭合的凝聚环.
- 这些修改后的凝聚体结构形成了二维DNA-凝聚体复合体.
- DNA-凝聚素复合体对蛋白质变性有抗性,支持陷模型.
结论:
- 凝聚蛋白环在物理上捕获了个别的姐妹微染色体DNA分子.
- 这项研究为姐妹染色体凝聚力的环捕获模型提供了直接证据.
- 这种机制对于维持细胞分裂期间的基因组稳定性至关重要.
相关概念视频
Cohesins
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesins
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Condensins
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
Condensins
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...

